Home / Media / Cistern Savvy; How Much Water can be Saved with Smart Flushing?

Cistern Savvy; How Much Water can be Saved with Smart Flushing?


  • Conservation
  • Product News
  • water

Water is widely considered to be earth’s most valuable resource. And the toilet is one of the largest water consumers across residential, healthcare, and commercial properties. So, for a quick-win when it comes to water-saving, here’s why it makes sense to look to the humble loo.

Water Saving Opportunities 

As we learn more about the consequences that water scarcity is having on our environment and understand the impact for the future, it is increasingly important to educate ourselves on water saving opportunities and choices.

A quick and effortless way to consume less water without giving it a second thought, is to install modern, water-saving flush and fill toilet solutions. But how much water, and money can be saved? 

When considering upgrading or replacing your toilet cistern, it’s important to think about the water efficiency of the system. The right specification can ensure that many litres of water are saved every day, with minimal effort.

Flushing Factors which Influence Water Saving

Across toilet cistern set-ups there are several variable factors which influence how much water (and money for those on a metre) can potentially be saved through the installation of efficient flushing and filling valves. 

These include: 

  • Current cistern arrangement
  • Size of cistern
  • Water pressure
  • Adjustment of settings on the valves
  • Efficiency of the specific valves which are installed
  • Cost of the water 

So, to help determine how much water, money and CO2 could be saved by upgrading your flush and fill valve, we have made some revealing calculations. Of course, the exact amount will vary depending on the factors above.

We have looked at an example calculation of the potential water costs and savings for a dwelling, occupied by four people, when the flush volume is reduced by up to 1 litre through installation of a more efficient flush valve like our Fluidmaster dual flush.

Up to an additional 1 litre per flush saving can also be made if the dwelling installs a Fluidmaster Airgap 6000 compliant water saving fill valve. 

Installation of both of these Fluidmaster valves together could reduce a person’s water consumption by up to 11.5 litres per day. Taking measures to cut individual water use by this amount, will achieve 28.5% of the Government’s 2050 water reduction target. 

The added benefit of fitting both valves to a dwelling with four occupants equates to a potential reduction in the water meter charge by up to £62.00 per year (depending on variable factors as listed above).

Did you know?….

  • WCs account for approximately 22% of domestic water use, with the average UK home flushing the WC 13 times per day (13 times per day is based on an occupancy of 2.3 persons; a 4-person dwelling will flush up to 23 times per day).
  • 59% of UK homes do not have a dual flush valve (source EST Water at Home Report).
  • Replacing inefficient or leaking fill valves with a compliant Fluidmaster Airgap 6000 water saving fill valve will reduce water consumption by up to 1 litre per flush, saving a 4-person home £31.20 per year off their water metre charge. The home’s carbon emissions will also reduce by 8.57kg per year. 
  • Replacing a single flush valve with a Fluidmaster water saving dual flush valve saves up to an additional 3 litres per flush and reduce water metre charges by up to £93.60 and carbon emissions by a further 25.72kg per year. 
  • The UK Government has set goals to curb the current daily water use per person from 145 litres to 110 litres by 2050. This equates to a 24% reduction in water consumption per person.
  • A reduction in domestic water meter charges for a 4-person home of circa £31.20 per year can be achieved by installing a Fluidmaster Airgap compliant water saving fill valve which saves 1 litre per flush.
  • The water industry uses up to 3% of total energy used in the UK.